The case of a four-year-old swine flu patient in Chennai has doctors wondering whether the H1N1 virus aggravated his ailment to the present “very critical but stable condition”.

The boy, admitted to a private hospital for kidney failure, tested positive for the flu and drifted into a critical state on Saturday after developing multiple organ failure. He has been put on a ventilator and is undergoing dialysis.

Noting that this is an atypical case, Director of Public Health S Elango said it was not yet clear if the virus had any role in worsening his condition. “We are sending the swabs to the National Institute of Communicable Diseases, Delhi, and National Institute of Virology, Pune, for revalidating whether he is H1N1 positive. Even if he is, we don’t know what role the virus played in aggravating his existing condition. We have to study it in detail,” Dr Elango told The Indian Express.

Of the 40 tested positive for the virus, only the boy’s condition has worsened, he noted, adding that the rest were responding well to treatment. Doctors said the child was an asthma patient, and had severe diarrhoea which subsequently affected his kidneys. The child’s family members were screened, and samples sent for testing.

Doctors also have doubts about the positive result of a 10-year-old girl from Coimbatore and have sent samples for revaluation. The result is expected on Monday.

In another suspected case, a four-year-old and his mother turned up at the CGMC with fever symptoms. The mother and son had gone to Mumbai to attend a function and returned on August 6. After having fever for a few days, they turned up for testing. In the same hospital, a 24-year-old woman from Erode, working as a software engineer in Mumbai, was admitted with symptoms of the flu.